Prediction of hard meningiomas: quantitative evaluation based on the magnetic resonance signal intensity

Background From a surgical perspective, presurgical prediction of meningioma consistency is beneficial. Purpose To quantitatively analyze the correlation between the magnetic resonance (MR) signal intensity (SI) or apparent diffusion coefficient (ADC) and meningioma consistency and to determine which MR sequence could help predicting hard meningiomas. Material and Method This study included 43 patients with meningiomas who underwent preoperative MR imaging (MRI), including T1-weighted (T1W) imaging, T2-weighted (T2W) imaging, fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), contrast-enhanced (CE)-T1W imaging, and CE-fast imaging employing steady-state acquisition (FIESTA). A neurosurgeon evaluated the tumor consistency using a visual analog scale (VAS) with the anchors soft (score=0) and hard (score=10). The SI ratio (tumor to cerebral cortex SI) and ADC value were compared with the tumor consistency. The sensitivity, specificity, and accuracy for predicting hard meningiomas (VAS score 8; 9 of 43 patients) were calculated using cutoff values for the SI ratio that were obtained in a receiver operating characteristic curve analysis Results A significant negative correlation was observed between the tumor consistency and the SI ratio on T2W imaging, FLAIR, and CE-FIESTA (P<0.05) but not on T1W imaging, CE-T1W imaging, and the ADC value. The sensitivity, specificity, and accuracy for predicting hard meningiomas were 89%, 79%, and 81% with T2W imaging; 89%, 76%, and 79% with FLAIR; and 100%, 74%, and 79% with CE-FIESTA, respectively. Conclusion Our results suggest that a quantitative assessment using conventional T2W imaging or FLAIR may be a simple and useful method for predicting hard meningiomas.